the invisible red thread
by bleufilms
Summary: AU; an invisible red thread connects those who are destined to meet, regardless of time, place, or circumstance. the thread may stretch, or tangle, but never break.
1. Chapter 1

**Disclaimer: Sadly, I don't own Castle neither any of the characters, everything belongs to ABC.**

 **Hey so I have been playing in my ins with this AU for a while now so I would seriously appreciate some feedback or just a review of what you think about the idea. Thanks and enjoy!**

* * *

"…and with great pleasure, may I present to you, Richard Castle."

The crowd roared, as he approached the microphone in the middle of the stage, but his eyes were trained to the floor and his thoughts anywhere but in the moment, hands drenched with sweat. He had never been nervous, he didn't even have a real reason to be. But when Gina bumped his side reassuringly as she passed by after introducing him, walking down the small stairs and joining the crowd, he jumped with surprise but quickly covered it and continued walking nonchalantly.

Castle looked up and plastered his usual charming smirk to the crowd, playing his very own real-life character like he always does. "Thank you everyone for coming in here…". The flashes continued but more scattered, his eyes already used to the blinding white lights.

His gaze traveled around the small black blobs facing him, but his eyes were only trained in his soon to be ex. Gina threw a tight lipped smile at him, trying to look cool but he knew she wasn't. She shouldn't even be here, it wasn't good for neither of them. The throb in head increasing, the continuous thump sounding louder and louder, her words echoing in his mind.

 _Rick, I can't do this anymore._

"I-I.. I couldn't have done this without all of my fans, the support of my family a-and.." He cut himself off. What were they now? Exes? Friends? Co-workers? He couldn't decide, he couldn't think. His mind swirled. Richard Castle, the worldwide famous writer, didn't have any words. Was that even possible? A writer not having any words? His eyesight started clouding, and his balance failing.

 _I can't do this anymore._

 _I can't do this anymore._

 _I can't do this anymore._

Her words constantly repeating themselves in his mind and the last thing he saw, was the concerned look on Martha, his mother, and her body kneeling beside him on what looked like the stage's wooden floor, flashes going off everywhere and Gina on the phone but a worried look plastered on her face.

* * *

The sound of clicking heels on pavement in crime scenes was now a common occurrence, its sound now bonded to the announcement of the arrival of Detective Katherine Beckett, from the twelfth precinct. She strode through the street, the dark New York City night surrounding her, but when she was just halfway to the body and Lanie Parrish, her best friend and one of the medical examiners and forensics analysts for the NYPD, her phone in her back pocket rang.

"Beckett." She answered, but when the hospital answered back and mentioned her dad's name, her cold stare turned into a tired look. Every time her mother's death's anniversary would approach, her father would seek comfort in alcohol and end up in the hospital with an alcoholic overdose. "I'm on my way." Her concern for his safety was still present in her heart and mind, but the remorse she had been building through this years was stronger and it was a tiring routine.

She turned around and trotted back to her car, seeing her co-workers Javier Esposito and Kevin Ryan making their way to the scene. "Cover for me, my father's at the hospital."

"Update us with his status!" Esposito shouted back at her but her ignition was already roaring and the car turning.

* * *

Parking in New York City was the worst. Finding any spots near a hospital in the city that never sleeps is impossible, so Kate was forced to leave her car 6 blocks away from the building. She turned the car key and just as she was taking it out, a drop fell on her windshield. She smiled, opened her door and felt the drizzle begin.

* * *

After being freed from his mother's smothering grasp, Castle managed to sleep half an hour before the first thunder woke him and everything, including his television, went dark. He pressed the button that was supposed to call a nurse but minutes passed and no one came around. Richard glanced around and soaked his surroundings but when he spotted the jug that was previously filled with water he sighed tiredly. "Seriously?"

His feet found the ground, his right hand molded onto the i.v stand whilst he used it as a cane. He headed outside his room, the hallway deserted. "Nurse?"

* * *

Everything was dark except for the lights from the streets and the lightening, guiding her through the empty hospital. She reached for a door but just when she was pulling it open, someone pushed it over her way, the door bumping hard against Kate's body.

"Ow! Watch it." She winced, the doorknob making contact with her stomach.

"I-I'm so sorry, are you okay?" He quickly extended his hand to cover hers on her stomach, but she pushed it away, her face still scrunched up in pain.

"Yes, yes I am." Beckett lied, her gut still throbbing, but when she looked up and was met with a man in a white robe she softened. "You- You're a patient. What are you doing out here? You should go back to your room and r-"

"Whilst I appreciate your concern, if someone else makes that suggestion to me today I might throw myself out of a window for a change." He interrupted, his sarcasm bubbling a surprising snort from the detective, surprising even herself. "I just want water."

She glanced to his i.v connected arm, her arms folded now and before she could reprimand how it wasn't possible for him to be thirsty he put his hand up silencing her. "I-I know it's not possible but I swear to you I'm thirsty. Look," He touched her arm but quickly retorted back when she flinched at the contact. "I know I'm a rude stranger who bumped and hurt your gut, but could you _please_ get me a glass of water whilst I ruthlessly redact my complaint to this damned hospital."

A soft smile crept on her lips, the anger on his face looked as it didn't fit, uncommon to his features such as the crinkles in his eyes signalling a lot of smiling. Despite of herself, she found herself nodding slowly, her eyebrow raised. "Okay."

* * *

When she came back, he was no longer standing in the middle of the hallway, but sitting on a bench just next to a window, looking mindlessly through the it and too lost in his thoughts to notice her approaching. Kate finally sat beside him, and the man looked up surprised but with a gentle smirk playing on his lips.

He grabbed the glass from her hands. "Thanks," He drank a few sips before humming in appreciation. "I was starting to think you had abandoned me." She rolled her eyes and soaked in the clouded view, rain falling fiercely.

"Big fan of rain?" He asked sarcastically, his eyes glued to her exquisite profile. Her perfectly shaped jawline that looked like it could cut like a knife drawing his attention, but his interests shifted when he caught sight of her alluring plump lips, curved in a slight grin.

Kate nods. "Every time it rained, my mom would pick me up from school and we'd go watch an old movie to the Angelika Theatre." Her grin grew with the memory, but the ball in her throat as well. "And if we were lucky enough, it would still be raining after the movie and we'd walk back home and let the rain wash everything away."

She swallowed the ball and the watering that was starting to form in her eyes, her mind catching up to her words, surprised by the sudden revelation to a stranger but, after all, he was just a stranger. She looks back to the man, who's smiling sweetly at her but she cuts the moment before it becomes emotional with a cough and changes the subject.

"So what are you in for? You aren't crazy, right?" She ventures playfully and he rolls his eyes.

"I'm not but I'm sure my daughter would disagree," He starts and her smile broadens. "I fainted during my book premiere, stress induced I think, maybe too much thinking."

Her eyebrows shoot up. "Wow. A writer, anything I've read?"

Her not recognising him surprised him, but he nods. "Richard Castle." He extends his hands and she takes it with wide eyes and immediately connects the dots. She had read that tonight was going to take place his premiere.

"Huh, hadn't recognised you. A pleasure Mr. Castle." She acts naturally, but her inner fan still makes her eyes shine and his real smile fades and turns into the signature smirk she had seen multiple times in pictures. But his face quickly crumbles and her eyebrows knit. "I-I don't mean to pry but.. is something bugging you, Mr. Castle? Any mysteries in your life yet to solve?" She playfully asks, trying to lighten the mood and it clearly works when his original smile spreads once again but with a sadder tone.

"Upcoming divorce and writers block aren't much of a mystery." He sighed and combed his hair with the hand free from the plastic cup.

Her smile drops. "I'm so sorry."

"Don't be, it's not your fault and it was doomed anyway. Has been doomed since the day I put a ring on her finger. Actually, if I think about it, we've been having problems since Alexis's 7th birthday. But with Derrick, everything was too easy, too predictable. Every mood, every- wow okay, I'm venting to a total stranger about my personal troubles I might be the most depressing person, ever. I'm sorry."

Wide eyes and both of her eyebrows hiked up to her hairline, Kate lets out a breath of understanding. "No, it's okay. You're clearly going through some things and feel the need to vent to someone."

He nods and drinks water, silence surrounding them but the sound of the rain hitting the concrete and ceiling.

Castle looks back at her before he speaks up. "Why does nothing turn out as we wanted as kids? I would always think, I'd meet someone, fall in love when I was young and that'd be it. Wouldn't you?"

Beckett takes a bit to respond, her eyebrows knitted, thinking of an answer. "I used to, I also used to think that everything would turn out as I wanted, but when I was younger I.. I lost someone very close to me. It changed what I used to think about life, how everything wasn't going to turn out how I wished it had. She would always tell me that life was kind of like a road trip, you know?" She looks at him and he is looking at her, soaking every word she says. "It isn't just about arriving at the destination, it's about enjoying all the way to it. Sometimes you get lost, you fight, you lose people, you take new roads, you learn new things along the way, you explore new places, you meet new people, and even if you're lucky you fall in love. But in the end, if you weren't enjoying the ride, what the hell were you doing?"

Castle breathes in, the words, her meaning and swallows it. He's not in a good place to be emotional so he lightens the mood. "I'm sorry, darling, I was just stopping for gas."

Her watery eyes brighten at the joke and she laughs, a sound so sweet and hypnotizing he is completely captivated by it. He smiles at her dreamily and she grins back, her laughter now dying. "What?"

He looks at her lips and back up quickly. "I don't even know your name and I want your number, maybe even go to dinner someday.."

Her heart skips a beat from his confession but it slowly wakes to reality when she remembers his tendencies before his marriage. He used to be a playboy, usually surrounded by blonde bimbos and drinking in parties, not her type. But the man she had barely met today was completely different to the man she originally imagined he was. But now, recently divorced, she knew it would only take a couple of weeks before he went back to his old habits. She smiled at him. "And what, Castle? Become one of your conquests?"

Castle smirks. "Or I become one of yours." He wiggles his eyebrows playfully, but his true intentions more than just a one night stand.

She shook her head slowly, rolling her eyes with a grin on her face. "You're not ready to date yet, Mr. Castle. But when you are, you'll find me. One way or the other."

He nods in defeat, but his smirk doesn't simmer, just softens into a sad one. "Too bad. It would've been great."

Kate bites her lower lip, a habit that draws Richard's gaze to her mouth. She stands up, plants a kiss to her cheek and leans in to his ear. "You have no idea." She whispers before walking away from him slowly, his eyes still trained on her as she heads to her father's room.

And then, as he watched her walk away, he knew she would be worth the wait.

Every. Single. Minute of it.

* * *

 **Review? Thoughts?**


	2. Chapter 2

**Disclaimer: Same as in chapter 1, Sadly, I don't own anything. Copyright to ABC.**

 **Author's note: First of all, thank you so much for all the amazing reviews! You guys are the best. I still haven't had time to check the other chapter's mistakes and I'm sorry if I make a lot of them, English isn't my first language.**

 **Anna: Thank you for pointing them out, I'll check them out later and in response to your question about the age difference, it's the same difference as in the show. Beckett's features in the story I imagine as similar to the ones in season 2, her hair a bit longer but still kind of short and reddish colored. As in the title of the story, I would like to explain its meaning but I don't want to spoil the rest of the story for the others so the explanation will eventually come as the story develops, so sorry.**

 **I'm inspired these days so enjoy these quick updated but don't get used to them!**

* * *

Kate pressed down the invisible wrinkles on her pants as she finishes getting ready to work, the sun rising from the horizon but she's already wide awake, already used to the early hours her job demanded. Her brown short bouncy hair in place, pink lips perfectly painted and finally felt ready to go.

She grabbed her purse, car keys and before leaving, she pressed a soft kiss to Tom's temple.

Tom wasn't supposed to happen, and the guilt was killing her, everyday getting worse and worse. It started with innocent dates, innocent kisses and went straight to sex from there. But after a month, she had made the mistake of getting attached and was heartbroken when weeks later he had a girlfriend.

She had drunk her feelings numb for a week, when he appeared in her door with flowers and promises of breaking up with her when she got better from her PSTD. Her inner voice shouting not to take him back was ignored by her dizziness and her desperate heart, begging for care and someone to distract her from her loneliness. She threw her arms around his neck and kissed him fiercely, and since that day they hadn't stopped sneaking around.

She glanced at her phone to re-read the address of the crime scene Esposito had texted her and headed to the parking lot.

* * *

"Mother, I'm fine." He tried to free himself from his mother's, _rather strong_ might he add, grasp.

"Nonsense, Richard. You fainted in your own book premiere, was hospitalised for 2 days and connected to an I.V. I think I've earned my rights as a mother to help her son install himself in his new home." Martha reprimanded to him complaints.

Castle sighed defeatedly, he loved his mother to death and was entirely grateful for her help throughout the day, but he was old enough to walk by himself. But Martha Rodgers was a persistent woman, and he caved easily to her and his daughter's, Alexis, wishes.

"To be honest, Richard, your divorce to this woman was kind of a relief, your stress levels were so high I could feel them before even entering your office.." _And here we go again_ , Richard sighed tiredly, the third time hearing that speech in a matter of days, knowing exactly every word by heart now, no new verses added.

As soon as they entered the loft, he headed to the spacious balcony, in need of fresh air, his mother dialing the phone to order their usual at Lucciano's. He wasn't in the mood for cooking and she knew her cooking wasn't good.

* * *

"Just, hurry up. You know where the bathroom is." She hissed to Lanie, her best friend, who apparently had a lunch date but her clothes had gotten stained in the crime scene. Kate had surrendered to her repeated pleads for another set of clothes and changing in her apartment.

Kate loved her with all of her heart but Lanie surely knew how devoted her best friend was to her work and leaving in the middle of a case wasn't Beckett's cup of tea.

The detective strolled to her balcony, grabbed with both of her hands and squeezed her eyes shut, exhaling through fully with her nostrils.

"Hey stranger." She heard a familiar voice say, just a few steps from her. Her eyes flew open in confusion.

Her head turned to her right, both of her brows knitter in amusement and confusion. "Castle?" A small tentative smile played on her lips. "W-what are you doing here? Coming to ask a stranger for another favor? Because if you are, I must say I didn't imagine you going on such lengths for a favor. "

He snorted lightly. "Oh, you wish." If it was possible, she looked even more beautiful than the night he had seen her. "I'm moving in here, with the divorce and all.. what, what are _you_ doing here?"

"I _live_ here." She challenged back, playfully. She could now see his features clearly. Tall, taller that she remembered, both corners of his eyes showing some crinkles, ghosting one of the smiles he had offered her just two nights ago and a pair of deep blue eyes she could easily get lost in… she shook her thoughts quickly.

"So, are you _finally_ going to tell me your name?" He asked with an innocent look and Kate rolled her eyes.

But when she opened her mouth to respond, she was interrupted by Martha striding in to the balcony. "Richard, would you be a dear and set the table whilst I- Oh!"

The older woman stopped for a second to study Kate and she nodded in acceptance as she drank in her figure. A sincere smile spread on her face and Martha extended her hand towards her, crossing the small wall that separated both balconies. "Hello, I'm Martha Rodgers, Richard's mother, and you are?"

Beckett's cheeks were now pink, but when she extended her hand to meet hers and answer her question, she was once again interrupted by her phone ringing. "I'm so sorry, Mrs. Rodgers, but I have to go back to work. It was nice meeting you and Castle, I-I guess I'll see you later." He nodded with a dumbfounded look on his face and she went back inside, slid her finger over the 'answer' sign and pressed her phone to her ear as she strolled to look for Lanie. " Espo, talk to me."

* * *

Castle followed the sway of her hips before she disappeared inside but was called back from his thoughts by his mother's fingers snapping infant of him. "Honey? Richard? Who is she?"

He smiled at the distance and looked back at his mother. "My new neighbour."

* * *

The day flew by, the suspect Esposito had called her in for during her lunch break finally caved after only 10 minutes of questioning. But it was still too early to go home, just a few minutes after 1pm, so Beckett stretched her muscles and spent the entire afternoon catching up in paperwork and organising her desk, activity she had been postponing for a few weeks now. Hours later, just as she was taking the last of the extra folders in her desk, Kate glanced at her watch.

6:00pm. She exhaled happily. _Finally_.

"Finished the paperwork, I'm going home." She declared to Ryan, Esposito having left early for the day.

Ryan nodded and glanced at the wall clock. "I'll join you, but would you wait just five minutes and we'll go?"

She nodded and checked if she was forgetting anything. 2 minutes later, Ryan was back with two plastic cups of coffee.

"Now, tell me, how is that a high class detective like -you- didn't recognise the famous Richard Castle until he _told_ you who he was." He nudged her side playfully, but careful not to spill any of the burning liquid in each cup.

She rolled her eyes. "Look, in my defence, it was very dark and he wasn't wearing any of his usual suits or shirt, but a white hospital camisole."

Kevin's right brow hitched, his smirk growing and a knowing look spreading across his features. She turned to look at him, eyeing him suspiciously, a lighthearted glare on her face. "What?"

He shrugged innocently. "Nothing.." He said and continued walking, Kate followed close behind with small hinges of curiosity in her mind.

* * *

3 hours.

3 whole hours had passed since his mother had left him alone to work on his new novel and nothing. Not a single word was written on his word document. Castle stared blankly at his computer but not a single word came to life.

Finally giving up, Castle closed shut his computer, and in the moment the screen made contact with the keyboard, all the big lights went dark once again.

"Oh you have _got_ to be kidding me."

* * *

"Oh you have _got_ to be kidding me." She heard Castle say. She had been sipping a glass of wine, finally relaxing in the solitude of her apartment, her new neighbour long forgotten until now.

She glanced to his apartment and caught a glimpse of him with an exasperated look on his face, so she headed inside, grabbed a flashlight and some candles, and headed next door.

She had only knocked once when the apartment B's door swung open, revealing and exhausted Castle in a white shirt and black plants. The frown in his face immediately melted at the sight of Kate and she smiled shyly, pointing the light that eradicated from her flashlight to her face. "Need any help?"

He nodded and stepped back to let her in. "Yes please" He affirmed. "I don't have any candles and I have very little battery percentage in my phone," He followed her outside to the balcony, his confusion growing when she approached a grey metal box and opened it. "and I'm afraid my mother will start worrying and come here tonight and-"

But his pleas were shut down by the switch of all the lights in his apartment back on and he looked at her in shock. She closed the box's door once again but with a smug smirk on her face. "Voilá!"

"H-how did you do that?" He asked, still amazed by her effectiveness.

She swung around with a smug look. "I've lived alone since I was 19, I had to learn how to survive, and knowing how to turn back on electrical plugs is living alone 101."

He nodded in understanding, a beautiful smile crept on his face. "Thank you." She nodded in unknowledgement.

"Your welcome, Castle." She smiled back. "Oh and that reminds me, it's Kate."

"I'm sorry?" He replied, confused.

"My name, Katherine Beckett."

"Kate." He repeated, amazed to finally know more about her, but his stomach grumbled and an idea popped to his head. "Despite of how -heartbroken- I still am for you turning me down the other day on the hospital," Castle feigned physical hurt, a hand clutched to his chest and Kate rolled her eyes in response. "I'm very grateful for your saving today so how about a friendly dinner between neighbours, I ordered take out just 20 minutes."

"Castle- I told you, I'm not going on a d-" He stopped the last word from coming through her lips, her divine, plump, splendid.. he shook his back to the present.

"It's not a date. I swear, Kate. Friends?" He asked, extending a hand to Beckett. She eyed it curiously, and looked back up to meet his gaze.

Oh, but what was the hell was she getting into, she had no idea. Kate bit her lip, stretched her hand and covered his with hers. "Friends."

After learning that their chinese delivery orders were almost the same, Castle uncorked a bottle of wine, took to glasses to the balcony where she was waiting with the food all settled, and they dined.

Talk came fluently, he ventured her in what was like being the son of Broadway star Martha Rodgers, told her everything about his daughter, her heart swelling whilst she listened to Castle beam with pride as he described endless stories about Alexis. And when it was her turn to tell him about her life, she started by her job, already bracing herself to hear his reaction. "I'm a homicide detective, I'm actually the youngest woman to make detective."

His eyes big as plates. "That's-that's.." _And here it comes_ , Beckett thought to herself. "So cool!" Her eyes now mimicking his.

"Wait what?" She gasped, surprised by his interest in her job. "Most men usually run when I tell them that."

"What are you talking about? You're like a mixture between my two favorite novel characters, James Bond and Sherlock Holmes. You're perfect." His mind making the perfect connection in his mind, already working on new ideas, not noticing Kate's tainted pink cheeks. "Tell me more, tell me everything."

Kate's smile spread happily through her face.

Tom slid open Kate's apartment's door with a bouquet of flowers and meowed. "Kitty? Are you up?"

He looked into her empty room in confusion, but when he heard laughs come from the balcony next door he recognized her giggle. His feet guided him outside, where he caught sight of Kate chatting with a man.

He coughed, bringing both of their heads to snap to his way. "Kitty? I'm home!"

"Tom?" Kate scrunched her face confused to see him this late at, she glances at her watch and-1:30am _when the hell had time flew by?_

"Tommy? Tommy Demming?" Castle recognized him and Tom's smile grew.

"Oh my- Richard Castle. I can't believe we finally meet again." Tom hugged him and he hugged back. "It's been years man!"

"It's been a long time, Demming." Castle nods nostalgically at him, they hadn't seen each other since Alexis's birth. He had come visit him to the hospital and to see Alexis, but after Tom being relocated to California, they had lost touch. "What are you doing here? Well, I mean, at Kate's apartment."

"Kate and I are dating." Castle's eyes widened, his mouth opening and closing and he directed his look at the detective. "What are _you doing_ here?"

"I just moved in, Gina and I are getting a divorce." He answered, but his mind connected the dots and he opened his mouth in realization. He leaned and whispered to his ear. "Does Kate know about Michelle?"

He nods but mouths at him _we'll talk tomorrow._

 _"_ So, beautiful? Coming?" Tom nodded towards Kate's apartment, calling her home.

She looked uncertain, may he even venture, dissapointed of having to leave. She stood up as Tom re entered her living room. She stood in front of Castle, who even in her heels still towered her. She leaned in and pressed a kiss to his cheek. A soft and breathtaking smile on her face. "Thank you, Castle. For tonight. For everything. I had fun."

He nodded numbly with a stupid smile, still hypnotized by the sent of cherries that evaporated from her and the soft press of her lips on his sizzling skin.

She headed to the door and just when she opened it, her head turned back and sent a smirk towards the still frozen writer in the middle of his balcony.

He wrote until 6am that night, already having written 2 whole chapters. Satisfied with his work he smiled in acknowledgement, he had finally found his muse.

* * *

 **Review?**


	3. Chapter 3

**Disclaimer: Same as in the previous chapters, I don't own anything bla bla bla, everything belongs to ABC.**

* * *

It's been a week since their spontaneous dinner that was rudely interrupted by his ex-bestfriend and her "boyfriend" _-phh_ , and his fingers can't seem to stop typing.

Of course, they have seen each other on the hallway, and sometimes they've chatted for a few minutes from their respected balconies, but she had been having a busy week always rushing to other places and work. Is it weird that he misses her? _Yes, yes it is._ _You barely know her_ , he thought.

An invitation to dinner at his house with him and Alexis was at the top of Castle's tongue, but he remembered he had planned to meet Gina and Paula tonight at ' _Florence_ ', a headache already starting to boil in his head, but he was kind of excited to tell them about his new character, Nikki Heat, so he smiled through the pain and continued typing.

* * *

Nothing, absolutely nothing.

Kate scanned the same channels for the third time and turned it off exhaustedly. Her mind still fuzzy with the accumulated exhaustion from this week. Her and the boys had been working on a case non stop, around the clock, but they were finally able to catch the killer when one of their main suspects alibi's was finally proved false.

Her arm extended to the coffee table infront of her and she grabbed the glass of wine she had served herself. The pinot had been open for over a week but she didn't mind. Her thought went immediately next door, to the amazing merlot that Castle had poured for both of them.

That night had proved how much she missed having someone that made her laugh. Of course, Lanie and the boys made her laugh, but it wasn't until Castle arrived that she noticed how much she yearned for being so relaxed and.. carefree.

She had felt it before, with Tom. Just before he had told her about Michelle.

Kate cringed at the thought of her, she gulped a big chunk of her wine and set it back down on the table once again. Sleep took over quickly, but just half an hour later she was woken by the horrible smell of something burning and a little girl's high pitched scream, the source of it all coming from next door and entering through her open window. But just before she could react, Beckett heard the next door's front door open, running footsteps approach hers and desperate knocking on her door.

Kate jumped from her place on her couch and sprinted towards it and when she swung it open, she was met with a little ginger with light blue desperate eyes. _This must be Alexis_ , she thought.

"Help, Miss Beckett! Please! The loaf is on fire!" Alexis grabbed her hand and pulled her towards her apartment. Confusion came and go in a flash, how the child knew her name she would never know, but she grabbed her keys and pulled the door closed whilst she let herself be guided to the apartment next to hers.

The door was already open, and as soon as she stepped in, she was welcomed by grey smoke that filled her nostrils and made her cough, but she followed it. Just before she got in the kitchen, she stopped and swirled to her right where Alexis was standing. Kate grabbed her shoulders and looked straight into her eyes. "Stay here, don't move."

The little girl had merely nodded when Kate went inside the kitchen, the fire bigger than she had pictured it, orange and angry. Martha was huddled in a corner coughing and the fire extinguisher on her hand but still secured and she looked like she had no idea how to use it. The detective crossed the kitchen in two long steps, grabbed the fire extinguisher from the woman's hands, pulled the security sting off, aimed the open mouth of it to the fire and pressed the handle, letting the white frozen foam do its job.

After a few seconds, the fire was out and Kate released the handle and the breath she hadn't realized she had been holding. The air was barely out of her lungs when she felt a pair of arms engulf her hips, Alexis's head pressed tightly against her ribs just below her breasts.

"Thank you, Miss Beckett. Thank you, thank you." Alexis breathed relieved, Beckett was taken aback by the gesture, but instantly relaxed into it and draped her own arm around her, squeezing her tightly and reassuringly.

"It's okay, everything's okay." Kate assured.

Martha's hand squeezed her shoulder with gratitude but her face showing she was still clearly shaken. "Yes, Katherine, thank you." She smiled but it quickly dissipated into a disappointed frown. "I mean, I knew my cooking wasn't the _best_ ," Kate could almost hear Castle's snort. "but being at risk for our own lives is a new limit."

Kate chuckled, the girl finally letting her go but her body still glued to the detective's side. "Please, Mrs Rodgers. Don't worry, it has happened to all of us at least once."

Martha smiled, satisfied by the comforting words of the woman. "I'd love to tell you to stay for dinner but.."

Oh, she shouldn't, but her idea was out of her mouth before she could stop it. "Actually, I was about to start cooking my own dinner, I haven't even started and I have enough to ingredients for more than just me, would you maybe like to join me?"

Both of the redheads's eyes brightened and Martha's smiled spread big enough to mimic the Cheshire Cat's.

"We wouldn't like to impose, but if you're inviting us we'd love to." The older woman deliberated, looking at Alexis's face for support and the girl nodded wildly and grinned.

They all headed to the door, Martha's hand grabbing the keys from the small handle next to the door before they forgot them. "Of course not, I wouldn't have invited you if you were. But- Oh! I _will_ need some help cooking.." Kate thought aloud, leading them to her apartment, her key already on the lock and turning, and the invite for Alexis to help her hanging in the air.

"Can I help grandma, can I? Can I? _Please_?" The little girl jumped and begged, her hands plastered together and shaking and a small pour on her lips. Alexis surely knew how to use the puppy face.

"Of course, honey." Her grandmother nodded and smiled when the little girl thanked her and shot into the apartment.

"And _you,_ Mrs Rodgers have to relax on my couch with a glass of wine." Kate said, with a quick glance and a wink to the older woman. But before Martha could complain, she stopped her with her hand. "Uh uh, chef's orders."

Martha chuckled, fascinated by the already growing bond between his granddaughter and her son's neighbour. She stopped Kate on the doorway by grabbing her wrist, confusion growing on the young woman's face. "Thank you, Katherine. And please, it's Martha."

* * *

The dinner had gone better than he had imagined, Gina and Paula were pleased with his new character and started pitching promotion ideas he didn't really care about so his concentration shifted to his dinner and drink and stayed there through the rest of the dinner. thank you leave early at one point and he was left alone with Gina.

The awkwardness faded after a few minutes of small talk, Gina asking about Alexis, about his new apartment and their nice and peaceful chit chat brought up a bloom of satisfaction on Castle's chest. They parted their ways outside the restaurant, and he smiled all the way back, until he reached his front door where he found a small sticky note stuck on the handle. He snatched it from its place and noticed Alexis's handwriting, surprisingly without spelling mistakes.

 _We're at Kate's having dinner. XO XO Alexis and grandma._

The smile on his face again, he pulled his keys back in his pocket as he strolled to the front door with the B on it. _B for Beckett._

His gentle knocks were followed by the sound of eager footsteps approach the door, swinging it open and his daughter jumping into his arms.

"Daddy!" she cried happily, his arms holding her in his chest.

"Hey munchkin, what are you doing here bothering Miss Beckett?" he entered the apartment and closed the door with his back, both arms around Alexis.

The small redhead unstuck her head from her father's neck with a shocked face. "We weren't bothering her, were we?"

She asked to the woman who was currently sipping from her glass of wine. Kate put the glass down and shook her head quickly with a small smile on her face.

"Of course not," she answered to the little girl but then looked at Castle. "I invited them after their incident."

His brow furrowed. "Incident?"

"Grandma's loaf caught on fire." Alexis said and his reaction must've been busy because his mother pulled her hand up in defense and quickly continued.

" _But_ Detective Beckett was kind enough to help us and invited us to dinner here."

Castle let out a sigh of relief and looked at Kate. "Thank you."

The detective smiled back, a small blush on her cheeks. _What the hell is all this blushing, Beckett, get a hold of yourself_.

Sadly, Alexis interrupted the moment with a big yawn. "Hey munchkin, want to go to sleep?" She nodded in the embrace. "Do you want daddy to tell you the gnome story he invented last week?"

"No," She said. "I want Kate to tell it." She requested, Kate's face like a deer in the headlights.

"Now honey, I don't think asking Kate to tell you a story after all th-"

"No, hey." Kate interrupted him. "It's fine, I can tell it." Alexis's sad frown turned into a big grin and she jumped from his fathers embrace to his grandmothers.

"Grandma help me get into my pajamas, please." The little girl asked and Martha nodded but just before leaving she came into a stop, grabbed the detective's hand across the bar table and squeezed it. "Thank you, again, Katherine." Her gentle and caring smile made Kate's heart swell.

She beamed at the moment with a pensive look but she startled when the water from her sink started running. She turned around and just behind the bar table where she was sitting that separated the kitchen and the living room, Castle was in the middle of scraping her dishes.

"I can do those myself, you know." She mused whilst grabbing her wine glass and drinking a small sip from it.

"You saved my daughter _and_ my mother's life today, cooked them dinner (which you lied to me because you said you didn't know how to cook), and survived an entire meal with my mother. I should be making you a god damn _monument_." He chuckled and her eyes rolled but a with smile on her lips.

"First of all I didn't _save_ them, I just used the fire extinguisher, second of all, I didn't _lie_ to you I just know how to cook two or three dishes and they aren't even that good, third, your mother is a great interesting and.. unusual woman. And last, what's this gnome story I have to tell Alexis? I haven't heard of it."

"Oh that's because _I_ invented it." Castle finished the last of the dishes, dried his hands on the dish towel next to him, turned around and sat on one of the barstools just in front of Kate's. "I invented this one last week, I tried to keep them original so she doesn't get bored, and surprisingly she liked this one so much she won't stop asking me to tell it again." Rick grinned at the thought and reminder of Alexis's excitement, and Kate smiled warmly at the loving father. "It's about a lone wolf, who was in charge of protecting the forest. He would roam the forest every night alone and make sure everything was okay. One day, during a dark stormy night, he looked up at the sky and saw a star. It was the most beautiful star he had ever seen." Kate's eyes shined, a tentative smile playing on her lips. "And in that same moment, he fell in love with her. From that night on, he would go each day to the same spot and howl at her but she would never respond."

Her smile faded, her eyebrows frowned in disappointment. She looked at her hands. "How does it end?"

Castle looked at her pensively, his mouth scrunched up to one side and he shrugged. "Wish I knew, Alexis always falls asleep before I can think of an ending."

"I don't like stories about impossible love." Kate sighed sadly.

"Who said it was?" he asked her, Beckett's eyes now on him. He leaned forward and whispered. "The only impossible things, are those we never try."

She nodded in acceptance, stood up and headed next door.

* * *

"The star stretched herself the longest she could and finally touched the wolf's snout, pressing a soft kiss to it. And in that moment, she realised, the only impossible things, are those we never try." Kate whispered to Alexis, sitting on the foot of her bed and combing the girl's hair. Alexis's body curled deeper to her toy bunny and Kate tucked her in. She placed a kiss to her temple before standing up and heading to the bedroom door where the writer was waiting for her. Her ears went red at the thought of him hearing repeat his words.

Castle reached behind her and closed the door softly. "You know, it's the first time that Alexis has asked for someone else apart from my mother and I to tell her a story. She wouldn't even let Gina." Kate's snort came a second to late before she could stop it. She covered her mouth with wide eyes, but Castle just smirked. Her eyes drifted to his mouth for a second and she shook her head.

"I-I have to go, it's getting late and I have to study for my test tomorrow so.."

"Test?" He asked.

"French. I took tomorrow morning off at work to take it." She sighed. "I've been studying for a couple of years now. My grandmother was French and it was very important to my mother."

"Was?" she asked and realisation hit him. "I'm so so sorry, Kate. When?"

"When I was 19, my father, my mother and I were supposed to meet at a restaurant to have dinner. After 2 hours we went back home, and when we reached our door a policeman was waiting for us." She swallowed. "She had been stabbed to death in the back of an alley, it wasn't a robbery because I love her things and money were still on her. I dropped law school and joined the police force, my father to get really bad and drowned his sorrows in alcohol. After a few years I got him to get better. _This_ is for the life I saved," She pointed at the watch on her left arm which belonged to her father _. "_ and _this_ is for the life I lost." She pulled out her necklace and picked at the ring that belonged to her mother _._

Rick nods with a sad look on his face, he presses his palm to her cheek and she lets her eyes flutter closed for a moment. Her breath shutters but she quickly composes herself and pushes his hand away.

"Anyway," She cleared her throat. "I-I should get going."

"Do you need any help?" He asked with a smirk.

"French kissing joke, Castle? Really?"

He shook his head with a chuckle. "I speak French too."

"Oh really?" She ventured and walked slowly to him.

"Oui." He nodded. "Pendant que ma mère répétait ses lignes toute la journée sur le plateau, je vivais pratiquement dans sa suite et son assistante était française alors elle me donnait des leçons et quelques années plus tard, quand nous avons lentement commencé à gagner de l'argent, je pouvais me permettre des cours."

Her eyebrows shot up impressed and grinned at the thought of a mini Castle practicing French.

"So? Need any help?"

"Oui, s'il vous plâit."

* * *

They spend the rest of the night practicing, it's after the 3rd cup of coffee around 3 AM when Castle suggests he make a fourth. She nods sleepily from the couch and he heads to the kitchen.

"You know, I was in love with my French teacher." He says to the small window on the wall separating the kitchen and the living room whilst he poured two coffee mugs. "My mother wasn't thrilled about it so she w-" he stopped on the spot when he Southgate leaning against the couch, fast asleep. "Kate?" He tried. "Beckett?" He tried again, and when no response came he put the mugs down and approached her, nudging her side slowly. Still no response.

Castle gave up, his gaze fixed on her gorgeous futures. He grabbed the blanket next to her and draped her with it. He combed back the hair on her face, press the ghost of a kiss on her temple and smiled. "Goodnight, Detective"

* * *

 **I really don't know any french so if any of those are wrong I blame google translator. Review?**


	4. Chapter 4

**Disclaimer: Same as in chapter 1, Sadly, I don't own anything. Copyright to ABC.**

* * *

After he left his apartment, Castle took Alexis to School and then met Tommy at a cafe. He's grasp on the flowers became stronger, squeezing it and ruining a couple of them.

 _"Look." Tom started with a sly smirk on his face. "What do you want to know? The sex? Two words:_ Mind _._ Blowing _." Richard flinched at the thought of them but quickly covered it with a playful smirk._

 _"Uh, no no. I just want to know what are your intentions with her." Castle folded his arms and rest his back on the chair._

 _His friend's eyebrows shot up. "What is this Ricky? An interrogation?" Tom chuckled. "You sound like a protective father."_

 _Castle shook his head. "I care about her." Tom's chuckle faded. "I-I mean, she saved my mother and daughter from a fire for god's sake plus she's a great neighbour.."_

 _At the last comment, relief took over Tommy's features and he smiled. "Whoo! You were scaring me there, Rick, I was starting to think you actually liked liked her."_

 _"Ha!" Richard laughed out loud, but more of it fake than real._

 _"Look man, it might have started just for the sex, but I'm crazy about her now, and leaving Michelle is in the works." Tommy grabbed his coffee mug and drank. "But you-oh yes! This is perfect!" Tom's mouth turned into a wicked grin and his eyes looked like he had just won the jackpot. "You are going to help me with Kate."_

 _Mid-drink, Castle spat some coffee onto the table, his face physically cringing. "_ What _? No. No way I'm getting into one of your messy relationships again."_

 _Tommy pouted. "Come on. Please, Ricky, for old time's sake! You just have to give us all the one on one space we need, for example, whenever she asks you to tag along with us, you politely say 'no, thanks.' Just small stuff, talk me up. Please."_

 _"Fine."_

 _"That's my boy."_

Everything about that conversation had gone to hell in his mind apparently because why was he suddenly waiting outside the french institute with a miniature bouquet of white clear jasmines on his hand, waiting for the woman that lived next door to his, to finish her exam.

But before he could back out, he saw her approaching with tears on her eyes on the verge from falling, and a frown on her face. _Oh._

She looked up and met Castle halfway with a confused look. "Castle? What are you doing here?"

He pointed to the bouquet with his head. "I came to surprise you. But, look, it's okay. You failed and you can take it ag-"

"I passed." Kate said calmly.

Castle's eyes illuminated and before he could congratulate her, he stuck the bouquet her way. "For you. Congratulations, Kate! But, why are you crying?"

"I'm just- so happy!" She grinned and snaked her arms around Castle's body. He hugged back but she realised her unexpected actions and broke it off quickly. "Thank you for these. You're really sweet."

Castle cleared his throat bravely. "Do you, uh, by any chance, want to come celebrate w-"

"Congratulations Kitty Kat!" Interrupted Tommy, appearing with a gigantic bouquet of red bloody roses. _Oh you have got to be kidding me._ She smiled happily and gave him a quick peck. "Thanks babe."

He grinned and slung one of his arms around her waist possessively. "Wanna go celebrate?"

"Yes!" She mused excitedly but looked at the writer. "Rick wanna come?

He _so_ wanted to go, but Tommy was shaking his head fiercely from behind her and his words resonated in his ears.

 _You just have to give us all the one on one space we need, for example, whenever she asks you to tag along with us, you politely say 'no, thanks.'_

He shook his head. "I-I'd love to but I just remembered I have to go.. but some stuff mother asked me to, so I'll see you later I guess."

The detective didn't believe a word, her eyes squinting and a confused frown scrunched up her face in disappointment. "Okay."

"Bye Rick!" Tommy waved with a wink.

The couple headed to the main street, just a couple of blocks away, and Kate's hands full with both bouquets.

* * *

After having coffee with Tom, Kate went back to her apartment to get her stuff ready for work. She put Tommy's get in a glass vase in the living room coffee table, and would castles small one in a big glass with water on her nightstand.

She smiled at his gesture and smell them. Her eyes drifted closed, the sweet smell feeling her nostrils, the image of his innocent figure standing outside of the Institute waiting for her would forever make her heart soar. She gave the flowers a small soft back and smiled.

* * *

The boys and Lanie took her out for lunch to celebrate, payed for her order at Remy's and gossiped about the unexpected surprise of the writer. They had a pretty relaxed afternoon. Esposito scrubbed the white board but it was useless, the words were stuck on it. _Permanent_ _marker_. His body deflating and his eyes rolled, he turned and headed to the supply closet but his body almost clashed with Beckett's.

"Looking for this?" Kate opened her hand full with cotton on one of her hands and alcohol on the other. Her eyebrow was popped with a knowing look and before the other detective could thank her she said.

"Go, I'll do it. I got night shift tonight."

Javier stopped and hesitated but tiredness took the decision for him instead. "Thanks, Beckett." He grabbed his jacket, slung his bag through his body and squeezed her shoulder on the way out.

Kate wet the cotton with some alcohol and started wiping off the suspect's names. After finishing with almost everything, she heard the elevator ding and footsteps approach.

"Bonne suit, mademoiselle." She heard Castle say as he steps became louder and headed towards her with a small basket on his hands and a petit wine bottle on the other. "I come bearing gifts."

She chuckled at the sight of him, stopping her movements when she noticed the white board was completely clean and threw the cotton ball in her trashcan. "How did you know I was here?"

"Well, as we didn't have a chance to celebrate earlier.." He started to take out food from the basket and placed it on her desk. "My fault know, so I came here to make it up for you. As far as your whereabouts, I called earlier to ask your boss at what time would your shift end tonight and when he said you would be working i thought of a different plan and came here."

She rolled her eyes with a smirk, the small invasion of privacy not bothering her in this case. She spotted her favourite french cheese on Castle's hand and she clasped her hands on it. "Oh my _god_ caprice de dieux my favourite _."_ She swooned and studied the rest of the food on her desk. A baguette, some salmon, beef and ham carpaccio, a variety of different cheeses that smelt amazing, two dips, two champagne glasses and the small wine bottle she had spotted earlier in his hand.

"Last time I went to France, I was there in a book tour and Alexis was four. So, in one of the free days I got in Paris, I took her to the Champ de Mars park, just below in front of the eiffel tower and we had a picnic there." He smiled at her and she mimicked. "It's one of my favourite moments with her, and I know this isn't Champ de Mars and we aren't laying in the grass in Paris but.." He trailed out and shrugged.

"It's perfect." She grinned and sat on the opposite side of her desk on Espo's chair. "Rick," She called his eyes to look at her, and not the damn cheese that could wait a second before it got cut. "Thank you."

Kate using his first name took Castle by surprise, his heart thumping thoroughly but he quickly shook it off.

 _"Whoo! You were scaring me there, Rick, I was starting to think you actually_ liked _liked her."_

"So," He changed the subject. "Tell me about today's case."

* * *

Conversation flowed, as always, naturally. Kate had laughed at his excitement for the 'traceless body', a body that literally had no way to trace it to know who it was, no foot prints, no handprints, and most importantly, no face. He grabbed a napkin and wrote some things and she frowned.

"What are you doing?" He finished writing and snuck two white styrofoam bowls from the picnic basket. _Ice cream_.

"Oh! I forgot to tell you all about her. You know, when we first met I told you about the writer's block?" She nodded as he opened one of the bowls, studied it for a second and gave it to her.

"Hmm?" She nodded and grabbed one of the spoons on the table.

"Gone. I finally found my new inspiration." He mused and she put a spoonful of ice cream _-ooh coffee, nice_ in her mouth.

"Yeah? What?" The frozen drink still in her tongue, the strong coffee taste making her moan in delight.

"You." He continued eating from his bowl but she froze- _no pun intended_.

" _Me_?" What do you mean me?" Beckett stuttered.

"Ever since that night when we had dinner at my place and you told me about you, what was like being a detective and everything, I can't seem to stop writing." He answered casually.

Kate looked at him, a breathtaking smile slowly spreading on her face, her eyes twinkling, she bit her lower lip and and squeezed it outside. _How could he be so cool with something so.._

She shook her head in disbelief and went along with his relaxed demeanour, putting another spoonful in her mouth. "What's it about?"

He looked afar as he pictured it, extending a hand dramatically. "It's about a crime solving detective called Nikki Heat and her plucky si-"

" _Nikki Heat?_ Change it." She sputtered.

"What? No! I can already picture the book series, Heat Wave, Raging Heat, Frozen Heat.."

She rolled her eyes. "It's a stripper name."

"No it's not. Although she _is_ kinda slutty."

" _EXCUSE ME?"_

He shrugged and she let out a spit of air. _Pff, slutty. He had some nerve._

Remembering about today's events, she couldn't resist asking. "Why did you lie today when I asked you to join me and Tommy?" She saw the lazy excuse on his lips but she stopped it with her hand. "Save it, I know you lied, Castle. Detective, remember?"

He scratched the back of his head and sighed. "I- okay, don't tell him I told you, but Tommy asked me to give you guys some space and let you have your time with him."

Kate's brow scrunched furiously and she gritted her teeth. "What?"

Castle sensed her anger and grabbed her hand, squeezing it and in seconds her anger dissipated. Her look went back into his eyes.

"Hey, no. Don't be angry with him, it was my fault. He's right, you guys deserve your space, and I'm- I don't even know what I was doing there in the institute, I totally overstepped-"

"No, don't say that." She put her wine glass down and put her other hand over his cheek softly.

Her eyes sparkling, the touch of her hand on his face magnetising and he slightly leaned into it. "I- really _really_ don't."

His eyes went to her lips whilst hers fluttered closed, both leaning in, faces just a few centimetres apart.

But the phone on her office rang and sprung them both to their respective chairs and she grabbed the handle of the phone. "Beckett." Her voice hoarse and she coughed it to covered it. "Yes, sir. Okay."

Her Captain, Roy Montgomery, had requested her to go organise the files from last week's case just in case the D.A came to collect them.

"I-i have to go back to work. You should get going, but thank you from everything. It was very.. sweet of you." Castle ate another spoonful of his chocolate ice cream and left the plastic spoon in the now almost empty bowl.

"Oh, i-it was nothing." _Lies_ she thought to herself whilst he prepared the basket to leave, but left both bowls on its place. He smiled at her one more time, standing just infant of her. "Goodnight."

Beckett saw the door of the elevator close in front of him.

Her pensive gaze drifted to his bowl, where his spoon lay and she extended her hand and grabbed it. Kate's gaze went back to the last place she had seen him, and put his spoon in her mouth, her tongue cleaning the rest of the ice cream from it.

"Goodnight."

It tasted like him.

* * *

 **Thoughts? Reviews really help with my motivation :)**


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